GB1586869A - Seat reclining mechanisms - Google Patents

Description

(54) SEAT RECLINING MECHANISMS (71) We, I.H.W. ENGINEERING LIMITED, a British Company of Stratford Road, Warwick, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly des- cribed in and by the following statement: This invention relates to a seat reclining mechanism and from one aspect is an improvement in or modification of the invention disclosed in Patent Application No.

5235/75 (Serial No. 1528357).

This earlier application describes a seat reclining mechanism in which two hinge members are pivotally interconnected by a shaft which mounts a sun gear. Planetary gears are engaged with the sun gear and also engage with two ring gears surrounding the planetary gears. These ring gears are mounted on the two hinge meabers respectively, the ring gears having a different number of teeth . A knob is mounted on the shaft to rotate the latter, the gear arrangement providing reduction gearing for angularly moving the hinge members.

In the specification, of the above referred to patent application, there is claimed a seat reclining mechanism comprising first and second hinged members, an internally toothed ring gear on each of the hinged members, one ring gear having more teeth than the other ring gear, a control gear located within the two ring gears, means for effecting drive between said control gear and said ring gears, which means include at least one planetary gear in mesh with both ring gears and the control gear, and means for rotating the control gear to effect relative angular adjustment of the two hinged members.

In the description of the invention in the aforesaid specification, there is described an arrangement for rotatably mounting the planetary gears on pivot studs on a carrier plate, so that the planetary gears are in mesh with the control gear, and the control gear in turn in mesh with the ring gears.

The present invention is concerned with an improvement in or modification of the invention described and claimed in the aforesaid specification, and in particular with the modification in or improvement of the support for the planetary gears within the ring gears. Accordingly, the present invention provides a modification of or improvement in the seat reclining mechanism claimed in the specification of Application No. 5235/75 (Serial No. 1528357) having a support member located between the control gear and the planetary gear, said support member having a concave surface receiving the planetary gear.

In a particular construction the planetary gears will be of a given width or thickness for meshing with the two ring gears. The control gear will be of approximately one third of the thickness of the planetary gears and two support members of substantially the same thickness and also of approximately one third of the thickness of the planetary gears, are provided either side of the control gear so that the control gear is in mesh with the planetary gears and the planetary gears which are freely located within the ring gears are in fact held in position by a concave surface on the support members. Desirably, four concave surfaces are provided so that four planetary gears are in mesh with the control gear and in turn in mesh with the internally toothed ring gears.

In order that the present invention may be more readily understood, reference is now made to the accompanying drawings in which: Figure 1 is a sectional view of a seat reclinking mechanism according to the present invention and Figure 2 is an elevation of a part of the mechanism on the line A-A of Figure 1.

The mechanism shown comprises a first hinge plate 11 for attachment to a back-rest (not shown) and a second hinge plate 12 for attachment to a seat (not shown), the plates being hinged together by a pin 13 having a head 14.

The first hinge plate 11 is fine-blanked to define a circular shoulder 16 opposite to a circular recess 17 and to define a first ring gear 18 having internal teeth 19. The second hinge plate 12 is also fine-blanked to define a circular recess 21 and a second ring gear 22 having teeth 23. The shoulder 16 is a close fit in the recess 21. The first ring gear 18 liars 25 teeth and the second ring gear 22 has 21 teeth. A support plate 25 is interposed between the head 14 and the second hinge plate 12.

The pin 13 has flattened portions 28, 29 and mounts a control gear 30 having a complementary aperture, so that rotation of the pin produces rotation of the control gear 30. The control gear is sandwiched between two support members 31a, 31b, to be fully described hereafter, the pin being rotatable within the members. The control gear has seven teeth 32.

Between the ring gears 18, 22 and the control gear 30, four planetary gears 35 to 38 are meshed, these planetary gears each having eight teeth and each engaging simultaneously with both ring gears.

A further retaining plate 40 is received by the pin 13 and engages in the recess 17 to hold the gears in position. A resilient washer 41 is located between a spacer 42 and the further retaining plate 40. A location washer 43 bears on the spacer and a nut 44 bears on the location washer through other washers 45, 46. A hand wheel 47 is mounted on the location washer 43 and held in position by a retaining washer 48 and a further nut 49 engaged on a pin 13.

The resilience of the washer 41 permits rotation of the pin 13 by turning of the handwheel 47. The control wheel 30 is thereby rotated and motion is transmitted through the planetary gears 35 to 38 to the ring gears 18, 22, so that a small angular move ment of the hinge plates ll, 12 is effected per revolution of the handwheel.

Each support member 31a, 31b, is cruciform and effectively is a disc-shaped member having a central circular aperture 50, indicated by dash-lines in Figure 2 and having cut-outs. The aperture 50 is complementary to the pin 13, but due to its circular shape, each support member is located by its aperture, but the pin can rotate within the member. The cut-outs are part-circular and are equi-angularly spaced, so as to define arms 51 and 54 and concave surfaces 55 to 58.

As shown in Figure 2, each planetary gear 35 to 38 is complementary to and is snugly received in contact with a respective one of the concave surfaces 55 to 58 of each of the support members 31a, 31b.

In use, the concave surfaces act as ramps, so that the planetary gears tend to climb these surfaces, this tendency serving to urge the planetary gears into mesh with the ring gears 18, 22 so that there is no slipping, even with considerable wear. The floating nature of the support members also compensates for wear on the gears and for manufacturing tolerances.

WHAT WE CLAIM IS:- 1. A modification of or improvement in the seat reclining mechanism claimed in the specification of Application No. 5235/75 (Serial No. 152837) having a support member located between the control gear and the planetary gear, said support member having a concave surface receiving the planetary gear.

2. A seat reclining mechanism according to Claim 1 in which the support member has four equally spaced concave surfaces for receiving the externally toothed gear surface of four separate planetary gears.

3. A seat reclining mechanism according to Claim 1 or Claim 2 in which the control gear is sandwiched between two support members.

4. A seat reclining mechanism according to any of the preceding claims in which the support member is substantially of cruciform appearance.

5. A seat reclining mechanism substantially described and illustrated here and with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. The first hinge plate 11 is fine-blanked to define a circular shoulder 16 opposite to a circular recess 17 and to define a first ring gear 18 having internal teeth 19. The second hinge plate 12 is also fine-blanked to define a circular recess 21 and a second ring gear 22 having teeth 23. The shoulder 16 is a close fit in the recess 21. The first ring gear 18 liars 25 teeth and the second ring gear 22 has 21 teeth. A support plate 25 is interposed between the head 14 and the second hinge plate 12. The pin 13 has flattened portions 28, 29 and mounts a control gear 30 having a complementary aperture, so that rotation of the pin produces rotation of the control gear 30. The control gear is sandwiched between two support members 31a, 31b, to be fully described hereafter, the pin being rotatable within the members. The control gear has seven teeth 32. Between the ring gears 18, 22 and the control gear 30, four planetary gears 35 to 38 are meshed, these planetary gears each having eight teeth and each engaging simultaneously with both ring gears. A further retaining plate 40 is received by the pin 13 and engages in the recess 17 to hold the gears in position. A resilient washer 41 is located between a spacer 42 and the further retaining plate 40. A location washer 43 bears on the spacer and a nut 44 bears on the location washer through other washers 45, 46. A hand wheel 47 is mounted on the location washer 43 and held in position by a retaining washer 48 and a further nut 49 engaged on a pin 13. The resilience of the washer 41 permits rotation of the pin 13 by turning of the handwheel 47. The control wheel 30 is thereby rotated and motion is transmitted through the planetary gears 35 to 38 to the ring gears 18, 22, so that a small angular move ment of the hinge plates ll, 12 is effected per revolution of the handwheel. Each support member 31a, 31b, is cruciform and effectively is a disc-shaped member having a central circular aperture 50, indicated by dash-lines in Figure 2 and having cut-outs. The aperture 50 is complementary to the pin 13, but due to its circular shape, each support member is located by its aperture, but the pin can rotate within the member. The cut-outs are part-circular and are equi-angularly spaced, so as to define arms 51 and 54 and concave surfaces 55 to 58. As shown in Figure 2, each planetary gear 35 to 38 is complementary to and is snugly received in contact with a respective one of the concave surfaces 55 to 58 of each of the support members 31a, 31b. In use, the concave surfaces act as ramps, so that the planetary gears tend to climb these surfaces, this tendency serving to urge the planetary gears into mesh with the ring gears 18, 22 so that there is no slipping, even with considerable wear. The floating nature of the support members also compensates for wear on the gears and for manufacturing tolerances. WHAT WE CLAIM IS:-

1. A modification of or improvement in the seat reclining mechanism claimed in the specification of Application No. 5235/75 (Serial No. 152837) having a support member located between the control gear and the planetary gear, said support member having a concave surface receiving the planetary gear.

2. A seat reclining mechanism according to Claim 1 in which the support member has four equally spaced concave surfaces for receiving the externally toothed gear surface of four separate planetary gears.

3. A seat reclining mechanism according to Claim 1 or Claim 2 in which the control gear is sandwiched between two support members.

4. A seat reclining mechanism according to any of the preceding claims in which the support member is substantially of cruciform appearance.

5. A seat reclining mechanism substantially described and illustrated here and with reference to the accompanying drawings.